Three glorious ceratopsian #dinosaurs! Only two bones are required to be a member of the horned dinosaurs: big jugal and a rostral bone. I have labeled them for each of these spectacular specimens. The jugal bone flares from the side of the skull. The rostral is the “upper lip,” a triangular-shaped bone that occupies the front of the upper jaw, unique to #ceratopsians. Psittacosaurus, “parrot lizard,” Osborn 1923 lived in the Early #Cretaceous of Mongolia (and elsewhere) 120-100 mya. Despite bei